I keep bleeding after ?

My bf and i have been together for sometime now and we just started having the first few times were just fine no problem. but now it seemed likes everytime we have i just start bleeding,and it keeps going on for about 5 or 6 days he is a little bigger then most men i have been with and we are use lubricant which i have used before but not as much as we do now it not my period it is like every week we try different things but it still comes out all the same what is wrong with me.